Effect of Coronal Temperature on the Scale of Solar Chromospheric Jets

Abstract

We investigate the effect of coronal temperature on the formation process of solar chromospheric jets using two-dimensional magnetohydrodynamic simulations of the region from the upper convection zone to the lower corona. We develop a new radiative magnetohydrodynamic code for the dynamic modeling of the solar atmosphere, employing a LTE equation of state, optically thick radiative loss in the photosphere, optically thin radiative loss in the chromosphere and the corona, and thermal conduction along the magnetic field lines. Many chromospheric jets are produced in the simulations by shock waves passing through the transition region. We find that these jets are projected farther outward when the coronal temperature is lower (similar to that in coronal holes) and shorter when the coronal temperature is higher (similar to that in active regions). When the coronal temperature is high, the deceleration of the chromospheric jets is consistent with the model in which deceleration is determined by the periodic chromospheric shock waves. However, when the coronal temperature is low, the gravitational deceleration becomes more important and the chromospheric jets approach ballistic motion.

A Three-dimensional Magnetohydrodynamic Simulation of the Formation of Solar Chromospheric Jets with Twisted Magnetic Field Lines

“…The closed loop also acts to heat the corona more easily. This prevents the nonlinear amplification of the chromospheric shock wave Iijima & Yokoyama 2015), leading to shorter jets. The numerical dissipation of the MHD scheme is also important.…”

“…The solar abundance is taken from Asplund et al (2006). The basic equations and numerical methods are essentially the same as those in Iijima & Yokoyama (2015). Additional details of the numerical methods are described in Iijima (2016).…”

Two-dimensional Radiative Magnetohydrodynamic Simulations of Partial Ionization in the Chromosphere. II. Dynamics and Energetics of the Low Solar Atmosphere

“…Despite the fact that the simulations are 2D, the corona is self-consistently maintained well above a million degrees. Previous 2D simulations required a hot plate at the top boundary in order to maintain a milliondegree corona (e.g., Heggland et al 2011;Leenaarts et al 2011;Iijima & Yokoyama 2015;Nóbrega-Siverio et al 2016). It was necessary to expand into three dimensions and have closed field lines, i.e., loops, in order to obtain a selfmaintained hot corona (e.g., Gudiksen & Nordlund 2002Hansteen et al 2010;Martínez-Sykora et al 2011;Carlsson et al 2016).…”

“…Previous 2D MHD simulations (Heggland et al 2011;Leenaarts et al 2011;Iijima & Yokoyama 2015;Nóbrega-Siverio et al 2016) have required a hot plate at the upper boundary in order to produce a hot corona. Previously it was only when computing 3D models that self-consistently heated coronae arose (e.g.,Gudiksen & Nordlund 2002; Hansteen et al 2010Hansteen et al , 2015Martínez-Sykora et al 2011;Carlsson et al 2016).…”

“…This model has the potential to resolve some of the remaining unresolved issues with respect to the impact of spicules on the TR and corona Madjarska et al 2011;Judge et al 2012). Other phenomena are better understood, but current models cannot fully capture some of their properties, e.g., the length and lifetime of dynamic fibrils (Suematsu et al 1995;Hansteen et al 2006;Heggland et al 2007;Martínez-Sykora et al 2009b;Iijima & Yokoyama 2015). The persistence of these unresolved issues in part stems from the difficulty of combining all these ingredients into a single numerical approach that models the full solar atmosphere and takes into account radiative transfer with scattering, thermal conduction, partial ionization effects, etc.…”